Topic: CB750K model tank question

[Bonafide]

Hey guys, I've been confused while looking for a replacement stock tank for my recently purchased 72 model. My tank has the petcock on the left side of the bike .. same as my 76 CB750F model - yes, different petcock, but same location. I saw a couple tanks listed on evilbay that are listed as a 750 and appear to be K models - but the petcock location is on the right side??

Is there some K tanks that had the petcock on the right side of the bike? This seems so odd to me.

BTW - if someone has or knows of a lead on a nice tank that fits a 72 750K ... PM me. Looking for one that is clean on the inside and dent free on the outside. Paint fade isnt an issue.

[MCRider]

Hey guys, I've been confused while looking for a replacement stock tank for my recently purchased 72 model. My tank has the petcock on the left side of the bike .. same as my 76 CB750F model - yes, different petcock, but same location. I saw a couple tanks listed on evilbay that are listed as a 750 and appear to be K models - but the petcock location is on the right side??

Is there some K tanks that had the petcock on the right side of the bike? This seems so odd to me.

BTW - if someone has or knows of a lead on a nice tank that fits a 72 750K ... PM me. Looking for one that is clean on the inside and dent free on the outside. Paint fade isnt an issue.

Yes the early K's had Right side petcocks, I'm surprised yours is left, that must be just at the model point where they switched. My 72 K2 had a Rt side petcock and in my rebuild I have bot a later left side tank.

When the cock is on the right and you run out of gas and have to go to reserve, it requires that you release the throttle to turn the cock lever, bummer especially in traffic.

Honda had a brain fart for a while as virtually all bikes of all years have left side petcocks.

Be careful buying a different tank. Theoretically all the Ks should interchange up to the 77/78 models. But they don't, they have minusule dimensional differences, I had to modify the mounts on my left side petcock tank to get it to fit my frame. Be ready to make some chops on the front and rear mounts. It will fit eventually.  They also changed the width of the front of the tank and later models have longer round rubbers.

[mystic_1]

Yes the early K's had Right side petcocks, I'm surprised yours is left, that must be just at the model point where they switched. My 72 K2 had a Rt side petcock and in my rebuild I have bot a later left side tank.

I don't disagree, but...... if you're sputtering cause you need to switch to reserve, then twisting the throttle doesn't do much of anything lol!  Being able to keep your left hand on the grip means you can pull in the clutch and coast until you switch to reserve.

mystic_1

[Bonafide]

Thanks Ron, for the amazingly fast response. Yes, the tank on my 72 has been changed to a later model. Looks more like a 74 model, but I'm not an expert on the stripes - etc. I would prefer a left side petcock - for the exact reason you stated, switching to reserve with my left hand vs my right.

The year of this bike is questionable. it's registered through the State as a 72 model, but the VIN would suggest it's a 71 model.

[MCRider]

Yes the early K's had Right side petcocks, I'm surprised yours is left, that must be just at the model point where they switched. My 72 K2 had a Rt side petcock and in my rebuild I have bot a later left side tank.

I don't disagree, but...... if you're sputtering cause you need to switch to reserve, then twisting the throttle doesn't do much of anything lol!  Being able to keep your left hand on the grip means you can pull in the clutch and coast until you switch to reserve.

mystic_1

Put a little English on the bike, lean it into the petcock and you can keep the throttle on with no loss of velocity. Change to reserve at leisure rather than panic. Helps when in fast moving Interstate traffic. I remember leaning it to the right, while going straight, keeping the throttle on, and reaching across with my left hand to turn it on reserve. That was the best system I came up with.

I would really hesitate to pull in the clutch for fear of being rear ended. IF you chop the throttle and pull in the clutch, the engine dies before you get reserve turned on. It will bump start easily of course, but too much excitement for me at 70+ MPH.

Those are just my memories from back when I rode Phaedrus a lot. I always said if I ever get around to rebuilding it, I'm getting a left side petcock.

[ekpent]

I believe that the 1976 750K had the petcock on the left.One outlet and fuel ran to a T splitter. Does the petcock screw on to a bung rather than mount with 2 screws from the inside.

[MCRider]

I believe that the 1976 750K had the petcock on the left.One outlet and fuel ran to a T splitter. Does the petcock screw on to a bung rather than mount with 2 screws from the inside.

Yes, besides moving it to the left side, and changing to 1 spigot from 2, the mounting changed to the ubiquitous "bung" rather than the seldom used 2 screw method.

[ev0lve]

Made the mistake of picking up a 73 tank for my 75. Petcock on the right. The side switch came in 74 I think. Left side from there on out.

[MCRider]

Made the mistake of picking up a 73 tank for my 75. Petcock on the right. The side switch came in 74 I think. Left side from there on out.

Many people don't care. If you do, as I do...bummer.

PS: If I'd thought of it, as I just did, a good tank man/welder could move the petcock for less than swapping tanks entails. You know, getting one, getting a petcock that works, paint, etc.   Double bummer. 

[ev0lve]

I would've gone with it but the intake for the carbs is on the left side and I didn't want to introduce any more weirdness to the machine than necessary by running a line 6 inches across the carb bank and making a hard 180.

There's probably a better way to do that if you do (move the inlet to between 3 and 4?) but I didn't mind being out $20 on that particular tank (dents).

One more thought on the left side petcock: they may have moved it but does anyone else find it a super pain to get to the idle screw with it on the left side (right behind the petcock)?

[myhondas]

I can say for sure that 69-74 had right side petcock. I can't remember if it was 75 or 76 that the switch was made.

[ev0lve]

75's definitely on the left so I suppose that's where the switch comes. CMSNL isn't much help - lists both petcocks on the fiche for 73 - 74 - 75